If "Batman v Superman" heralded, as the subtitle of that exercise in doom and gloom stated, the "dawn of justice," then the 2016 movie's sequel, "Justice League," suggests that it's still not quite morning in America.

To be sure, the latest film from DC Entertainment, the parent company of Batman and Superman's home, DC Comics, is measurably brighter and more fun than the last outing. That's due in no small part to the ray of sunshine brought to the franchise by Gal Gadot's Wonder Woman, an incandescent character featured only sparingly in "BvS" but who appeared in her own stand-alone hit this summer. Yet at the same time, "Justice League" suffers from the apparent determination by DC Entertainment to double down on the darkness, ceding the battle to weaponize action and humor to its rival in the superhero trade, Marvel. Fans of the tongue-in-cheek tone set by Marvel's recent "Thor: Ragnarok" — which seems to get the root meaning of the term "comic book" — will find little to laugh at, let alone love deeply, in "Justice League," which, like many a political speech, is long, loud, self-important and overly expository.

Picking up where "BvS" left off, "Justice League" opens with an extended series of short, scene-setting vignettes, starting with a snippet of a video podcast interview, made by kids, with Superman (Henry Cavill), who, as fans will remember, met an unhappy end at the conclusion of last year's film. This flashback prologue to one of DC's marquee superheroes — one known for his sunny attitude, until he snapped the neck of an enemy two movies ago — is followed, in rapid succession, by several grim and confusing scenes: a rooftop encounter between Batman (Ben Affleck) and a winged, insectlike alien; a battle between Wonder Woman and bomb-toting terrorists; and, later, a visit by Batman's now-bearded alter ego, Bruce Wayne, to a fishing village in Iceland, where Bruce tries to recruit a long-haired, tattooed recluse called Arthur Curry (Jason Momoa) for an as-yet-unnamed alliance of vigilantes.

A world without Superman, it seems, is desperately in need of replacements.

Arthur, who is soon revealed to be the amphibious Aquaman from the lost underwater world of Atlantis, has been delivering fish to the starving Icelandic villagers in an act of altruism that seems, in hindsight, somewhat heartless, given that he can communicate with marine life. Would you eat something you can have a conversation with? "I hear you can talk to fish," Bruce says, casting a quizzical look at Arthur, in one of the few instances where it's okay to chuckle at the dialogue. Later, explaining nothing, Aquaman states that it is the water, not him, that speaks to the fishies.

Other prospective members of the crime-fighting unit — which at this point consists only of Batman and Wonder Woman, who, despite a couple moments of goo-goo eyes, have zero chemistry — include the super-speedy slacker Barry Allen, a.k.a. the Flash (Ezra Miller), and the cybernetically enhanced brooding loner Victor Stone, a.k.a. Cyborg (Ray Fisher).

Did I say crime-fighting unit? The protracted formation of the movie's titular league may be the engine that drives the plot, but the foe that Batman, Wonder Woman and company are up against this time is no mere criminal mastermind, as Jesse Eisenberg's Lex Luthor was last time. Here, like Thor, he is the literal God Steppenwolf from the planet Apokolips. Voiced by Ciarán Hinds, Steppenwolf is a pure CGI creation: an ax-wielding giant in a helmet who has managed to assemble three alien "mother boxes" that will give him the power to destroy Earth, for reasons that remain murky. What is a mother box? Unclear. But it has something to do with the ability to replicate, on Earth, "the primordial hellscape of Steppenwolf's birth-world," as Wonder Woman puts it.

You can thank screenwriter Chris Terrio, who also worked on "BvS," for that turgid dialogue gem. There are also some funny zingers in the script every now and again, but I suspect that they come mostly courtesy of Terrio's co-screenwriter Joss Whedon. The writer-director of "Avengers: Age of Ultron" was brought on to put the finishing touches to "Justice League" when its director, Zack Snyder, left during post-production after his daughter's death. There's a bit of a steep learning curve to the resulting narrative, at least for viewers who don't bring an encyclopedic knowledge of DC Comics lore to the film. References to such characters as the villain Darkseid — Steppenwolf's nephew, who doesn't even appear in "Justice League," although his name gets dropped — are likely to fly over most people's heads, while tantalizing DC Comic die-hards about sequels to come.

Most of the brights spots in "Justice League" involve Miller's Flash — literally. When Batman finally tracks him down, the superhero — who moves faster than the eye can see, and channels lightning-like electricity — is living in a sordid squat. The 20-something hipster, who looks like a Starbucks barista, is only too happy to join the team. "Stop right there," he tells Batman, interrupting the sales pitch like Renée Zellweger to Tom Cruise in "Jerry Maguire." "I'm in."

Barry needs friends, he tells his new Tony Stark-like patron, even if having them means overcoming a phobia about "bugs, guns and unusually tall people." This is a problem, in a film with a bad guy who's 15 feet tall, surrounded by minions that look like robotic dragonflies and ballistics aplenty. Miller's weird, antiheroic Flash is one of the most refreshing breezes to blow through "Justice League," making three years seem a long time to wait for the character's 2020 stand-alone film.

The special effects are adequate, and there are some exchanges of amusing repartee between the other members of the Justice League, even if the camaraderie seems stiff, by, say, the standards of an "Avengers" film. (Batman ribs Wonder Woman because she is still pining over her late love from a century ago, and she socks him in the ribs.) As most fans already know, the plot includes efforts to resurrect Superman, who can be seen in the film's trailer and who initially returns in a very different version — something closer to the resuscitated pets of "Pet Sematary," as Barry wryly observes.

Such darkness may be exactly what DC's fanboys and fangirls want. That was certainly the case for Christopher Nolan, whose noirish "Dark Knight" trilogy satisfied an apparent longing for cynicism and moral contradiction. But the more general audience — one that has developed a taste for Marvel's blend of jokes served alongside the justice — will just have to wait, if they haven't already given up hope.

PG-13.  Area theaters. Contains sci-fi violence and some coarse language. 119 minutes.